Namespace embedded coverage target

CMakeLists.txt

@@ -305,7 +305,14 @@ if(Python3_FOUND)
     # The script configures and drives its own instrumented build tree (under
     # ${CMAKE_BINARY_DIR}/coverage) so this build's binaries and its coverage
     # counters can never be stale or half-instrumented. Reports via gcov.
-    add_custom_target(coverage
+    # Keep the convenient generic name at the top level, but namespace it when
+    # embedded so a parent project can provide its own coverage target.
+    if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
+        set(AKERR_COVERAGE_TARGET coverage)
+    else()
+        set(AKERR_COVERAGE_TARGET akerror_coverage)
+    endif()
+    add_custom_target(${AKERR_COVERAGE_TARGET}
         COMMAND ${Python3_EXECUTABLE}
                 ${CMAKE_CURRENT_SOURCE_DIR}/scripts/coverage.py
                 --source-root ${CMAKE_CURRENT_SOURCE_DIR}